littlefs-project/littlefs
1
0
Fork 0
mirror of https://github.com/littlefs-project/littlefs.git synced 2025-10-14 02:43:30 +08:00
Code Issues Packages Projects Releases Wiki Activity

Fixed a double deorphan caused by relocation mid dir remove

Browse Source 
Long story short: There is a specific case where removing a directory
can trigger a deorphan pass, but lfs_remove did not check for this,
would try to clean up the (already cleaned) directory orphan, and
trigger an assert:

  lfs.c:4890:assert: assert failed with false, expected eq true
      LFS_ASSERT(lfs_tag_size(lfs->gstate.tag) > 0x000 || orphans >= 0);

The specific case being a remove commit that triggers a relocation that
creates an orphan.

This is also possible in lfs_rename, but only if you're renaming a
directory that implies a remove, which is a pretty rare operation.

---

This was probably an oversight introduced in the non-recursive commit
logic rework.

Fortunately the fix is to just check if we even have an orphan before
trying to remove it. We can rely on this instead of the file type, so
this fix shouldn't even increase the code size.

Found and root-caused by Hugh-Baoa
This commit is contained in:
Christopher Haster
2025-05-03 17:20:02 -05:00
parent 0634d13e07
commit a3d6bec5f0
1 changed files with 7 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
lfs.c
View File

@@ -3932,7 +3932,9 @@ static int lfs_remove_(lfs_t *lfs, const char *path) {
}
lfs->mlist = dir.next;
if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
if (lfs_gstate_hasorphans(&lfs->gstate)) {
LFS_ASSERT(lfs_tag_type3(tag) == LFS_TYPE_DIR);
// fix orphan
err = lfs_fs_preporphans(lfs, -1);
if (err) {
@@ -4076,8 +4078,10 @@ static int lfs_rename_(lfs_t *lfs, const char *oldpath, const char *newpath) {
}
lfs->mlist = prevdir.next;
if (prevtag != LFS_ERR_NOENT
&& lfs_tag_type3(prevtag) == LFS_TYPE_DIR) {
if (lfs_gstate_hasorphans(&lfs->gstate)) {
LFS_ASSERT(prevtag != LFS_ERR_NOENT
&& lfs_tag_type3(prevtag) == LFS_TYPE_DIR);
// fix orphan
err = lfs_fs_preporphans(lfs, -1);
if (err) {